US5851452A - Process for coating droplets or nanometric particles - Google Patents

Process for coating droplets or nanometric particles Download PDF

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US5851452A
US5851452A US08/586,731 US58673196A US5851452A US 5851452 A US5851452 A US 5851452A US 58673196 A US58673196 A US 58673196A US 5851452 A US5851452 A US 5851452A
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polymer
droplets
process according
solvent
particles
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Jose Alberto Vallet Mas
Francisco Javier Galan Valdivia
Nuria Carreras Perdiguer
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Alcon Cusi SA
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Laboratorios Cusi SA
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
    • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
    • A61K9/51—Nanocapsules; Nanoparticles
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
    • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
    • A61K9/51—Nanocapsules; Nanoparticles
    • A61K9/5107—Excipients; Inactive ingredients
    • A61K9/513—Organic macromolecular compounds; Dendrimers
    • A61K9/5146—Organic macromolecular compounds; Dendrimers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, polyamines, polyanhydrides
    • A61K9/5153—Polyesters, e.g. poly(lactide-co-glycolide)
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02—Making microcapsules or microballoons
    • B01J13/20—After-treatment of capsule walls, e.g. hardening
    • B01J13/22—Coating
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/70—Nanostructure
    • Y10S977/773—Nanoparticle, i.e. structure having three dimensions of 100 nm or less
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/70—Nanostructure
    • Y10S977/788—Of specified organic or carbon-based composition
    • Y10S977/795—Composed of biological material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/84—Manufacture, treatment, or detection of nanostructure
    • Y10S977/89—Deposition of materials, e.g. coating, cvd, or ald
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/84—Manufacture, treatment, or detection of nanostructure
    • Y10S977/89—Deposition of materials, e.g. coating, cvd, or ald
    • Y10S977/891—Vapor phase deposition
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/902—Specified use of nanostructure
    • Y10S977/904—Specified use of nanostructure for medical, immunological, body treatment, or diagnosis

Definitions

  • the present invention is comprised within the technical field of microencapsulation, particularly, in the coating of droplets of particles with sizes comprised within the nanometric range, using biodegradable and bio-compatible polymers of different nature.
  • the thus obtained products have important applications in pharmacy, medicine, cosmetics, veterinary, chemical industry, agriculture etc.
  • EP Patent 0274961B1 (which corresponds to U.S. Pat. No. 5,049,322) describes a method for the obtention of vesicular type, spherical particles having a size less than 500 nm.
  • the method comprises the preparation of a phase containing a polymer, an oil and a substance to be encapsulated in a solution or dispersion.
  • the phase is added, under agitation, to another phase formed by a non solvent of the polymer and of the oil, producing the precipitation of the polymer and subsequently the removal of the solvents by lyophilization.
  • the size of the reactor which contains the mixture is increased depending on the final volume desired. This implies the necessity of a scaling to adapt the manufacturing conditions.
  • the present invention relates to the coating of already formed droplets or particles, so that it is not necessary to agitate the mixture, which is effected by incorporation of the two phases in a device in which the mixture flows continuously, with the immediate production of the evaporation of the solvents.
  • the elaboration and facility conditions (reaction volume) is always the same, independent of the final volume to be obtained, so that it does not require scaling for the obtention of industrial quantities.
  • the solvent remains in contact with the recently coated vesicules during a very short period, so that the re-dissolution of the coating and the possible extraction of the active principle to the external phase is avoided, whatever the volume to be prepared.
  • FR A2 515960 allows the obtention of poly alkyl-cyanoacrylate biodegradable nanocapsules, which separate from the polymerization of the corresponding monomer. These nanocapsules contain a biologically active substance.
  • the disadvantage of this method is that it requires a polymerization stage, so that it can only be used with specific polymers. Besides this important limitation, it involves the difficulty of controlling the polymerization and the possible existence of residual monomers which may, in some cases, be toxic.
  • the present invention has the advantage that it does not require a polymerization, being a more rapid process and being applicable to a great number of polymers of diverse nature.
  • EP 0480 729 A1 The process described in EP 0480 729 A1 consists of the coating of droplets in oil, containing active principles for oral administration, with a polysaccharide with chelator capacity (sodium alginate) which hardens on the addition of multivalent cations, resulting in micro-capsules with sizes over 1 ⁇ m. Finally, it is lyophilized to obtain a product in powder form.
  • This method is limited to the employment of polysaccharides with chelator capacity. Likewise, sonication is necessary, not being applicable for those active substances which are degraded by ultrasonic action. Additionally, the use of a multivalent cation solution makes difficult its employment in any form other than oral.
  • the present invention provides coated droplets with sizes appreciably below 1 ⁇ m, does not require hardening agents, does not use sonication, and the product obtained may be administered orally, parenterally, or through the nose, eyes, skin, lungs or any other form of administration.
  • microcapsules with sizes between 25 and 100 ⁇ m with oil inside, are obtained when dried by atomization and oil/water emulsion formed by the active principle and a gastroresistant polymer aqueous solution, producing a fine powder, by means of the use of an atomizer at a temperature of 140° C.
  • the use of high temperatures is a disadvantage since it limits the use of this method when the encapsulated substance is thermosensitive.
  • This method is only usable for water-soluble polymers, and additionally differs from the object of the present invention in that the sizes obtained are much greater.
  • the present invention is a method which allows the obtention of large quantities of the product without changing the conditions or facilities, and consequently, is easily industrialized. This method allows the rapid and continuous coating of temperature or sonication-sensitive active substances, resulting in a final product which is usable in any field, and especially in the pharmacy and veterinary field.
  • the present invention concerns to a new process for the coating of droplets or particles with sizes below a micrometer, which contain, or are formed, of one or various chemical or biologically active substances. Consequentially, the present invention allows the obtention of particles or droplets coated by one or various biodegradable and/or bio-compatible polymers with diameters comprised within 100 and 100 nm, preferably within 200 and 500 nm.
  • a fine dispersion of droplets or particles is prepared.
  • the active substance is dissolved in a lipidic substance (generally an oil) or in a substance at fusion point below the temperature of the dispersing means.
  • the droplets may also be consist of the actual active substance.
  • these may be the actual active substance or have the active substance dispersed inside. They may also be part of a microorganism or integral microorganisms with sizes below one micrometer.
  • the dispersing phase is constituted by a solvent and a non solvent of the polymer which forms the coating and, optionally, contains one or more surfactant or suspending agents (PHASE 1).
  • the relationship between the solvent and the non solvent in PHASE 1 must be the adequate one, so that the coat-forming polymer does not precipitate when mixed with the phase which contains the polymer.
  • the phase which contains the coat-forming polymer (PHASE 2) is prepared by dissolving the coat-forming polymer in a solvent equal to the one used as part of PHASE 1, or any other which is miscible in a high relationship with the solvent of the polymer used in PHASE 1.
  • PHASE 1 and PHASE 2 are lead through separate tubes to a mixing zone, where they continuously contact without agitation or ultra-sonication, keeping their relationship constant (which avoids the instantaneous precipitation of the polymer) and the volume of the mixture.
  • the polymer does not deposit on the droplets or particles, though the deposition process may be initiated, which occurs instantaneously when the mixture is pulverized in an evaporation system with temperature and vacuum conditions allowing the rapid evaporation of the polymer solvent, which provides for the immediate deposition of the polymer around the droplets or particles.
  • part of the non solvent, or the totality of the same may be eliminated until a concentrated or dry product is obtained.
  • the conduction of the phases towards the mixture device zone may be carried out be means of any pumping system, or with the help of pressure or vacuum.
  • the relation between the solvent and the non solvent of the coat-forming polymer in the initial dispersion must be adequate so that when in contact with the phase which contains the polymer in the solution, the immediate deposition of the polymer tends to precipitate in the mixture of the phases, the small dimensions of the mixing zone allows the entrance of the phases in the mixing zone, and their exit in the form of powder through the other end is so rapid that the polymer has no time to precipitate. In this way, an uncontrolled precipitation is avoided which would produce the formation of aggregates, and it ensures that the coating is produced at the amount of pulverization or nebulization.
  • the selection of the solvent and the non solvent of the polymer in the initial dispersion is carried out depending on the chemical and physicochemical characteristics of the polymer, or the oil or lipidic substance, and of the active substance to be incorporated.
  • the non solvent may be a more or less complex aqueous solution, and the solvent may be any organic solvent which is miscible with a high relationship in water, capable of dissolving the polymer.
  • the solvent of the polymer may be for instance, an alcohol such as ethanol, methanol, isopropanol, a ketone of low molecular weight such as acetone or methyl ethyl ketone or any other solvent such as acetonitrile or tetrahydrofuran.
  • the solvent of the polymer has a dielectric constant over 15.
  • the aqueous solution of the initial dispersion must be adjusted to a pH and/or temperature at which said polymer is insoluble to ensure the deposition of the polymer when the solvent is evaporated during the pulverization.
  • the lipidic substance to be dispersed in the water may be a natural oil such as coconut oil, soya oil, olive oil, castor-oil, a mixture of capric acid tristearates and capric acid with glycerol, a mixture of saturated and unsaturated acid fats C 12 -C 18 where the main constituent is the linolenic acid (48%), a mixture of unsaturated poly-glycosided glycols consisting of glycerols and polyethylene glycol esters, a mixture of saturated poly-glycosided C 8 -C 10 glycerols, a palmitate ester of glycerol formed by mono, di and triglycerols of natural C 16 and C 18 fatty acids, or a mixture of the same, a mineral oil or a phospholipid.
  • a natural oil such as coconut oil, soya oil, olive oil, castor-oil, a mixture of capric acid tristearates and capric acid with glycerol,
  • the concentration of the lipidic substance in the final product is comprised within 0.1 and 10% (w/V), preferably within 0.5 and 5% (w/V).
  • the surfactant or emulgent agent of PHASE 1 may be amphoteric such as soya or egg lecithin, anionic such as sodium laurysulfate, cationic such as benzalkonium chloride or non ionic such as sorbitan monoleate, sorbitan monestearate, a polysorbate or a copolymer of polyoxyethylene-polyoxypropylene or a mixture of the same.
  • amphoteric such as soya or egg lecithin
  • anionic such as sodium laurysulfate
  • cationic such as benzalkonium chloride
  • non ionic such as sorbitan monoleate, sorbitan monestearate, a polysorbate or a copolymer of polyoxyethylene-polyoxypropylene or a mixture of the same.
  • the suspending agent may be a dextran, poly-vinylic alcohol, a cellulosic derivative, or a natural rubber such as xanthene rubber. Any of these may be used in combination with a surfactant agent enumerated above.
  • the surfactant or suspending agent concentration in the final formula is comprised between 0.01 and 10% (w/V).
  • the polymer used may be a synthetic polymer such as the glycols derived from propiolactone, butyrolactone and the epsilocaprolactone; a hemisynthetic polymer such as cellulose acetobutyrate, ethylcellulose, hydroxpropylmethylcellulose acetophtalate; the acrylic acid copolymers and the acrylic polymer, lactic acid copolymers with the glycol acid or the polycaprolactone.
  • Other polymers which may be employed are the cellulose acetophtalate, the polyanhydrides, the polyalphahydroxy-acids and the natural polymers.
  • the concentration of the coat-forming polymer in the organic phase is comprised between 0.01 and 5% (w/V).
  • Different forms of mixing the two phases exist. It may be performed through two parallel tubes, producing the union in a concentric or "Y" shaped zone, in such a way that the two phases are joined simultaneously.
  • the volumes of the phases may be equal or the volume of one phase may be greater with respect to the other.
  • the mixing zone has, on the extreme end at which the phases are incorporated, a suitable device, so that the mixture exists in powder form towards an evaporation system in which the solvent of the polymer is totally eliminated and, optionally, part of, or the whole of, the non solvent under reduced pressure and at a temperature below 50° C.
  • the degree of vacuum and the temperature must be adjusted depending on the solvent and the immediate deposition of the polymer around the droplets or particles is ensured, and the formation of aggregates or the appearance of uncoated particles is avoided.
  • the product thus obtained may be used in suspension or dry powder form, be extruded, compressed or granulated and be used alone or as part of a more complex blend.
  • the values of the average size and the polydispersity of the uncoated oil droplets are greater than those of the coated oil droplets, and these, in turn, are greater than the nanosphere.
  • the Z potential (parameter which indicates of the electric load on the surface of the droplets and particles), is -18 mV for coated droplets, while for the free oil droplets, it is -8 mV and for the nanosphere it is -14 mV.
  • the values of size, polydispersity and Z potential correspond to the average of 10 measurements.
  • the uncoated oil droplets (A) appear as uniform particles which adapt with one another, while coated oil droplets (B) appear as particles with a less dense core, surrounded by a transparent zone limited by a dark edge (polymeric coating).
  • a nanoemulsion of a mixture of caprylic acid and caprynic acid triesters was prepared with polycaprolactone-coated glycol, containing indomethacin at 0.1% (w/V) according to the process detailed in the description of the present invention.
  • the results are represented in Table II and in FIG. 2.
  • Table II the average size values and the polydispersity values of the uncoated oil droplets are greater than those of the coated oil droplets and these, in turn, are greater than those of the nanospheres.
  • the average size and the polydispersity of the nanosphere mixture and the uncoated oil droplets give intermediate values to those corresponding to the separate products and greater than those obtained for the coated droplets.
  • the nanaosphere and nanoemulsion mixture showed a bimodal distribution (two populations of particle sizes).
  • the values obtained for the mixture of the nanospheres and the uncoated oil droplets are within the values corresponding to each product separately.
  • the Z potential of the coated droplets is greater (in absolute values) than those of the nanospheres, the uncoated droplets and their mixture. Consequently, the product obtained by the process of the present invention is not the result of a mixture of precipitated polymer particles (nanospheres) and of uncoated oil droplets.
  • the values of size, polydispersity and Z potential correspond to the average of 10 measurements.
  • the nanospheres (NS) show a white sediment at the bottom of the tube, while the nanoemulsion (NE) shows a whitish float.
  • the nanosphere and nanoemulsion mixture (NS+NE) presents both a sediment and a floating, as well as a practically transparent intermediate liquid.
  • the coated oil droplets (NC) show a minimum sediment and floating but the intermediate liquid is much cloudier (whitish).
  • This intermediate coat which is wider and cloudier, corresponds to the coated oil droplets with an intermediate density between that of the oil droplets (less dense) and that of the nanospheres (denser).
  • FIG. 1 represents uncoated oil droplets which appear as uniform particles which adapt with one another; and 1(B) represents the coated oil droplets which appear as particles with a denser core, surrounded by a transparent zone limited by a dark edge (polymeric coat).
  • FIG. 2 shows a comparison of the appearance of the intermediate liquid in test 2, between the nanospheres (NS), the nanoemulsion (NE), the mixture of nanospheres and nanoemulsion (NS+NE) and the coated oil droplets (NC).
  • Miglyol 812® (Dynamit Nobel, Sweden): is a mixture of caprylic acid triesters and caprynic acid with glycol.
  • linolenic acid is a mixture of saturated and unsaturated fatty acids C 12 -C 18 where the main constituent is linolenic acid (48%).
  • Eudragit L 12 5 (Rohm Pharma, Darmstadt): is a polymerized anionic of methacrylic acid and methyl methacrylate.
  • Lutrol F68 (BASF, Germany): is Poloxamer 188 which is a copolymer of polyoxyethylene and polyoxypropylene.
  • Lutrol F 68® 0.625 g is dissolved, under agitation, in 62 ml of deionized water and filtered through 0.22 ⁇ m.
  • Miglyol 812® dissolved in 62 ml of acetone.
  • the acetonic solution is incorporated to the initial acqeous solution under magnetic agitation, so that a dispersion of droplets with average size below 1 ⁇ m is obtained (PHASE 1), 0.312 g of polyepsiloncaprolactone is dissolved in 125 ml of acetone with the help of ultrasonication (PHASE 2).
  • the two phases are continuously mixed through the two parallel tubes, maintaining the relation of the phase constant in the mixing zone and pulverizing the resultant mixture towards the evaporation system simultaneously to the formation of the mixture.
  • the evaporation system removes under reduced pressure and at a maximum temperature of 45° C., the acetone (polymer solvent) so that the deposition of the polymer around the oil droplets is produced and part of the water (non-solvent of the polymer) is eliminated until a final volume of 25 ml is reached.
  • the average size of the coated droplets measured in a Zetasizer 3 (Malvern Instruments, England) was 192 ⁇ 0.1 nm.
  • Example 2 the ratio of solvents in the initial dispersion is of 2:3 water/acetone expressed in volumes, instead of 1:1 water/acetone.
  • Example 1 The technique described in Example 1 is followed, but using 0.830 g of Lutrol F68®, 0.207 g of polylactic-glycolic copolymer instead of polyepsiloncaprolactone and 0.415 g of Miglyol 812®.
  • Lutrol F68® 0.375 g Lutrol F68® was dissolved in 40 ml of deionized water and filtered through 0.22 ⁇ m under agitation. 0.030 g of carteolol base was dissolved in 0.375 g of commercial linolenic acid, and the resultant solution is added to 60 ml of acetone. The acetonic solution was incorporated into the initial aqueous solution under magnetic agitation to obtain a dispersion of droplets with average size below 1 ⁇ m (PHASE 1). 0.187 g of polyepsiloncaprolactone was dissolved in 100 ml of acetone with the help of ultrasonication (PHASE 2).
  • the two phases were continuously mixed through two parallel tubes, while maintaining the ratio of the phases constant in the mixing zone, and pulverizing the resultant mixture the evaporation system simultaneously with the formation of the mixture.
  • the acetone was removed (solvent of the polymer), under reduced pressure and at a maximum temperature of 45° C., so that the deposition of the polymer around the oil droplets was produced and part of the water was removed (non-solvent of the polymer) until a final volume of 25 ml is reached.
  • the average size of the coated droplets measured in a Zetasizer 3 (Malvern Instruments, England) was 375 ⁇ 3 nm.
  • the ultrafiltering-centrifugal technique was used, determining, by means of HPLC, the concentration of carteolol in the total formula and in the filtration.
  • the percentage of the encapsulation of the carteolol was calculated by the difference between the concentration in the total formula and that of the filtration.
  • the percentage of encapsulation was of 70%
  • Lutrol F68® 1.66 g of Lutrol F68® was dissolved in 100 ml of deionized water and filtered through 0.22 ⁇ m under agitation, 0.050 g of indomethacin was dissolved in 0.83 g of Miglyol 812® with the application of heat, and the resultant solution added to 100 ml of acetone.
  • the acetonic solution was incorporated into the initial aqueous solution under magnetic agitation, so as to obtain a dispersion of droplets with average size below 1 ⁇ m (PHASE 1), and 0.415 g of polyepsiloncaprolactone was dissolved in 200 ml of acetone with the help of ultrasonication (PHASE 2).
  • the two phases were mixed continuously through the two parallel tubes, maintaining the ratio of the phases constant in the mixing zone and pulverizing the resultant mixture towards the evaporation system simultaneously with the formation of the mixture.
  • the acetone was removed (solvent of the polymer), under reduced pressure and at a maximum temperature of 45° C., so that the deposition of the polymer around the oil droplets was produced and part of the water was removed (non solvent of the polymer) until a final volume of 50 ml was reached.
  • the final pH was adjusted to 5.5 with HCl 0.1M.
  • the average size of the coated droplets, measured in a Zetasizer 3 (Malvern Instruments) was 551 ⁇ 15 nm.
  • the ultrafiltering-centrigal technique was used, determining by means of HPLC, the concentration of indomethacin in the total formula and in the filtration.
  • the percentage of encapsulation of the indomethacin was calculated by the difference between the concentration in the total formula and that of the filtrate. The percentage of encapsulation was 99%
  • the two phases were continuously mixed through the two parallel tubes constantly maintaining the ratio of phases in the mixing zone and pulverizing the resultant mixture towards the evaporation system simultaneously with the formation of the mixture.
  • the acetone solvent of the polymer
  • the acetone solvent of the polymer
  • the average size of the coated droplets was of 832 ⁇ nm.
  • Example 6 The technique described in Example 6 was followed, but substituting the Miglyol 840® commercial linolenic acid for the Miglyol 840®, and 0.030 g of carteolol base was included in the oil.
  • the ultra-filtering-centrifugal technique was used, determining, by means of HPLC, the carteolol concentration in the total formula and in the filtration.
  • the percentage of encapsulation of the carteolol was calculated by the difference between the concentration in the total formula and that of the filtration. The percentage of encapsulation was 66%.
  • Lutrol F68® 0.125 g was dissolved, under agitation, in 40 ml of deionized water and filtered through 0.22 ⁇ m. To this solution was added 100 ⁇ m of polystyrene latex with an average particle size of 200 nm and a Z potential of -30.81 mV measured in a Zetasizer 3 (Malvern Instruments) and subsequently 20 ml of acetone was added, to obtain a dispersion of droplets with average size below 1 ⁇ m (Phase 1). 0.01 g of polyepsiloncaprolactone was dissolved, by means of ultra-sonication in 25 ml of acetone (Phase 2).
  • the two phases were continuously mixed through the two parallel tubes, maintaining the relationship of the phases constant in the mixing zone and pulverized the resultant mixture towards the evaporation system simultaneously with the formation of the mixture.
  • the acetone solvent of the polymer
  • the acetone solvent of the polymer
  • the average Z potential of the coated droplets measured in a Zetasizer 3 (Malvern Instruments) was 28 6 ⁇ 1.5 mV.
  • Example 8 The same procedure for Example 8 is followed, but replacing the polyepsiloncaprolaotone with Eudragit L 12.5 P.
  • the initial solution of water and Lutrol F68 was adjusted to approximately pH4.

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US08/586,731 1994-05-20 1994-09-30 Process for coating droplets or nanometric particles Expired - Fee Related US5851452A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
ES09401121A ES2078190B1 (es) 1994-05-20 1994-05-20 Procedimiento para el recubrimiento de goticulas o particulas de tamaño nanometrico.
ES9401121 1994-05-20
PCT/ES1994/000085 WO1995031975A1 (es) 1994-05-20 1994-09-30 Procedimiento para el recubrimiento de goticulas o particulas de tamaño nanometrico

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US20030195133A1 (en) * 2002-04-10 2003-10-16 Adi Shefer Targeted controlled delivery compositions activated by changes in pH or salt concentration
AU2001240753B2 (en) * 2000-03-02 2005-04-14 Ethypharm S.A. Lipid nanocapsules, preparation method and use as medicine
US20050095189A1 (en) * 2003-09-26 2005-05-05 Brey Larry A. Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US20070207079A1 (en) * 2005-01-04 2007-09-06 Brady John T Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
WO2008010788A3 (en) * 2005-07-18 2008-10-23 Univ Massachusetts Lowell Compositions and methods for making and using nanoemulsions
US8318181B2 (en) 2005-12-01 2012-11-27 University Of Massachusetts Lowell Botulinum nanoemulsions
US8359820B2 (en) 2010-01-13 2013-01-29 Dohrmann Daniel R Ultra-low flow agricultural pump with unobstructed flow path and electronic flow control, tank refill indication, and detection of loss of flow
US9486409B2 (en) 2006-12-01 2016-11-08 Anterios, Inc. Peptide nanoparticles and uses therefor
US9486408B2 (en) 2005-12-01 2016-11-08 University Of Massachusetts Lowell Botulinum nanoemulsions
US9724299B2 (en) 2006-12-01 2017-08-08 Anterios, Inc. Amphiphilic entity nanoparticles
US10016451B2 (en) 2007-05-31 2018-07-10 Anterios, Inc. Nucleic acid nanoparticles and uses therefor
WO2020005402A1 (en) * 2018-06-28 2020-01-02 Idealchain, Llc Encapsulation system and method
US11311496B2 (en) 2016-11-21 2022-04-26 Eirion Therapeutics, Inc. Transdermal delivery of large agents
US11525139B2 (en) 2016-08-23 2022-12-13 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject
US11807867B2 (en) 2020-02-21 2023-11-07 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject

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ATE366932T1 (de) * 1998-11-30 2007-08-15 Nanosphere Inc Nanopartikel mit polymerschalen
DE19856432A1 (de) * 1998-12-08 2000-06-15 Basf Ag Nanopartikuläre Kern-Schale Systeme sowie deren Verwendung in pharmazeutischen und kosmetischen Zubereitungen
WO2003037359A1 (fr) * 2001-10-29 2003-05-08 Chengdu Somo Namotechnology Co., Ltd. Nanoparticule de composants de medicaments insolubles et procede de production correspondant
BR102015032910B1 (pt) 2015-12-29 2021-03-09 Companhia Nitro Química Brasileira processo de obtenção de uma dispersão coloidal, dispersão coloidal e seu uso
WO2018180966A1 (ja) * 2017-03-28 2018-10-04 富士フイルム株式会社 マイクロカプセル及びその製造方法

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US6372077B1 (en) 1996-03-12 2002-04-16 Berhan Tecle Method for isolating ultrafine and fine particles and resulting particles
US6190731B1 (en) * 1996-03-12 2001-02-20 Berhan Tecle Method for isolating ultrafine and fine particles and resulting particles
AU2001240753B2 (en) * 2000-03-02 2005-04-14 Ethypharm S.A. Lipid nanocapsules, preparation method and use as medicine
US7053034B2 (en) * 2002-04-10 2006-05-30 Salvona, Llc Targeted controlled delivery compositions activated by changes in pH or salt concentration
US20030195133A1 (en) * 2002-04-10 2003-10-16 Adi Shefer Targeted controlled delivery compositions activated by changes in pH or salt concentration
US8618020B2 (en) 2003-09-26 2013-12-31 3M Innovative Properties Company Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US8664148B2 (en) 2003-09-26 2014-03-04 3M Innovative Properties Company Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US20050095189A1 (en) * 2003-09-26 2005-05-05 Brey Larry A. Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US7727931B2 (en) * 2003-09-26 2010-06-01 3M Innovative Properties Company Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US20100197481A1 (en) * 2003-09-26 2010-08-05 3M Innovative Properties Company Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US7989384B2 (en) * 2003-09-26 2011-08-02 3M Innovative Properties Company Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US8314048B2 (en) 2003-09-26 2012-11-20 3M Innovative Properties Company Catalysts, activating agents, support media, and related methodologies useful for making catalyst systems especially when the catalyst is deposited onto the support media using physical vapor deposition
US8314046B2 (en) 2005-01-04 2012-11-20 3M Innovative Properties Company Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
US8058202B2 (en) * 2005-01-04 2011-11-15 3M Innovative Properties Company Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
US20070207079A1 (en) * 2005-01-04 2007-09-06 Brady John T Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
US8518854B2 (en) 2005-01-04 2013-08-27 3M Innovative Properties Company Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
US8664149B2 (en) 2005-01-04 2014-03-04 3M Innovative Properties Company Heterogeneous, composite, carbonaceous catalyst system and methods that use catalytically active gold
US10016364B2 (en) 2005-07-18 2018-07-10 University Of Massachusetts Lowell Compositions and methods for making and using nanoemulsions
CN101384247B (zh) * 2005-07-18 2013-05-22 麻萨诸塞州洛厄尔大学 制备与使用纳米乳剂的组合物和方法
WO2008010788A3 (en) * 2005-07-18 2008-10-23 Univ Massachusetts Lowell Compositions and methods for making and using nanoemulsions
US9486408B2 (en) 2005-12-01 2016-11-08 University Of Massachusetts Lowell Botulinum nanoemulsions
US10576034B2 (en) 2005-12-01 2020-03-03 University Of Massachusetts Lowell Botulinum nanoemulsions
US8318181B2 (en) 2005-12-01 2012-11-27 University Of Massachusetts Lowell Botulinum nanoemulsions
US10532019B2 (en) 2005-12-01 2020-01-14 University Of Massachusetts Lowell Botulinum nanoemulsions
US10905637B2 (en) 2006-12-01 2021-02-02 Anterios, Inc. Peptide nanoparticles and uses therefor
US9724299B2 (en) 2006-12-01 2017-08-08 Anterios, Inc. Amphiphilic entity nanoparticles
US9486409B2 (en) 2006-12-01 2016-11-08 Anterios, Inc. Peptide nanoparticles and uses therefor
US10285941B2 (en) 2006-12-01 2019-05-14 Anterios, Inc. Amphiphilic entity nanoparticles
US10758485B2 (en) 2006-12-01 2020-09-01 Anterios, Inc. Amphiphilic entity nanoparticles
US10016451B2 (en) 2007-05-31 2018-07-10 Anterios, Inc. Nucleic acid nanoparticles and uses therefor
US8359820B2 (en) 2010-01-13 2013-01-29 Dohrmann Daniel R Ultra-low flow agricultural pump with unobstructed flow path and electronic flow control, tank refill indication, and detection of loss of flow
US11525139B2 (en) 2016-08-23 2022-12-13 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject
US11781145B2 (en) 2016-08-23 2023-10-10 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject
US11993777B2 (en) 2016-08-23 2024-05-28 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject
US12071627B2 (en) 2016-08-23 2024-08-27 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject
US11311496B2 (en) 2016-11-21 2022-04-26 Eirion Therapeutics, Inc. Transdermal delivery of large agents
WO2020005402A1 (en) * 2018-06-28 2020-01-02 Idealchain, Llc Encapsulation system and method
US11807867B2 (en) 2020-02-21 2023-11-07 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject
US12077773B2 (en) 2020-02-21 2024-09-03 Akouos, Inc. Compositions and methods for treating non-age-associated hearing impairment in a human subject

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FI961348A0 (fi) 1996-03-25
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EP0717989A1 (en) 1996-06-26
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HK1017807A1 (en) 1999-11-26
OA10257A (en) 1997-10-07
CN1130868A (zh) 1996-09-11
KR960703577A (ko) 1996-08-31
ES2078190A1 (es) 1995-12-01
EP0717989B1 (en) 2001-01-10
DE69426568T2 (de) 2001-08-23
AU696400B2 (en) 1998-09-10
FI961348A (fi) 1996-03-25
DE69426568D1 (de) 2001-02-15
DK0717989T3 (da) 2001-05-21
PT717989E (pt) 2001-06-29
ES2078190B1 (es) 1996-08-01
BR9407333A (pt) 1996-06-18
CA2167681A1 (en) 1995-11-30
BG100372A (en) 1996-12-31
GR3035655T3 (en) 2001-06-29
HU9600386D0 (en) 1996-04-29
AU7537994A (en) 1995-12-18
ATE198548T1 (de) 2001-01-15
PL312666A1 (en) 1996-04-29
WO1995031975A1 (es) 1995-11-30

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